A bitter stalemate over how to build the Southwest Corridor light-rail line is adding nearly $1 million a week to its cost, perhaps as much as $21 million since project planners last fall postponed a decision on the final design.

Those costs reflect inflation estimates and come on top of the price of adding more costly features like tunnels in an effort to satisfy critics.

Moreover, if the dispute kills the project, $30 million in state and local funds already spent on it would be lost.

The continued haggling over the route and other aspects have raised concerns about the escalating cost of the Twin Cities' largest transit project, and how much power Minneapolis has to shape the outcome.

"I'm concerned that we will study this project to death and it will never get built," Metropolitan Council Member Jennifer Munt, whose agency is planning the project, said last week.

The statement stems from a disagreement between Minneapolis and St. Louis Park on whether to reroute freight trains to make room for the light-rail line in Minneapolis. They are among five cities along the proposed route from downtown to Eden Prairie whose consent must be sought by the Met Council before it can start building the line.

Signaling growing frustration, some metro officials on a panel that bankrolls Twin Cities transit projects and spent millions on Southwest are exploring whether the Met Council could override a city that refuses consent.

A bid for peace

Unsuccessful efforts to settle the freight train dispute helped drive up the cost of the proposed Southwest Corridor light-rail line last fall from $1.25 billion to $1.55 billion. Planners proposed spending more money to either reroute the freight from the Kenilworth corridor of Minneapolis to St. Louis Park or build light-rail tunnels next to the freight and recreational trails in the corridor. But Minneapolis didn't want the tunnels and St. Louis Park didn't want the freight.

Saying the project was in jeopardy, Gov. Mark Dayton in October supported a three-month moratorium to conduct more studies of tunnels and freight reroutes.

The results didn't change the positions of Minneapolis or St. Louis Park. But the Met Council estimates that construction costs increase by $40 million to $50 million due to inflation over the course of a year, meaning a three-month delay for studies late last year would add $10 million to $12.5 million by the time construction begins.

Inflation would add another $6.6 million to $8.3 million for an additional two-month delay in the project to explain the results of the studies at public meetings early this year.

The agency's estimates are based on the assumption that transportation construction costs will rise from 2.5 percent to 3.2 percent annually, faster than overall inflation. Construction costs rose 2.6 percent nationwide in the past 12 months, according to Engineering News-Record.

Aside from inflationary increases, the Met Council paid a consultant $22,000 to help calm critics at the meetings where the studies were released.

Falling behind

Southwest planners are counting on the federal government to pick up half of the cost of the project.

Southwest was among 10 transit projects in the nation that the federal government approved for preliminary engineering.

In the past year or so, eight of those have progressed to more advanced engineering or received final approval for federal funding.

Southwest and a trolley extension in San Diego remain in the preliminary phase.

Southwest can't proceed until it resolves the dispute over freight. Supporters worry about the competition.

"There are going to be a lot more people going after the same pot of money," Hennepin County Commissioner Peter McLaughlin told the panel that bankrolls metro transit projects.

That panel, the Counties Transit Improvement Board (CTIB), has spent $18 million since 2012 to help pay for preliminary engineering. That money comes from a quarter-cent sales tax in the five-county Twin Cities metro area that is used for transit improvements.

Hennepin County, where the line will run, has spent another $6.8 million and the state spent $5.4 million on the early engineering.

Focus on Minneapolis

Much of that work has been on developing options for rerouting freight or digging light-rail tunnels. After St. Louis Park objected to a reroute that would have put freight on two-story berms near homes and a school, the Met Council offered a new version that many city residents still found unacceptable.

Now the agency and area leaders are mulling a new tunnel plan that would run light-rail trains under a water channel in the Minneapolis Kenilworth corridor to satisfy critics who objected to the light-rail trains surfacing from tunnels to cross a bridge over the channel.

Tunneling under the channel could add $40 million to $85 million to an earlier tunnel option rejected by Minneapolis.

"I think it's going to take some leadership by folks in Minneapolis to recognize that freight rail is not going to move," Hennepin County Commissioner Mike Opat, a member of CTIB, said after a board meeting last week.

Ramsey County Commissioner Jim McDonough, also a CTIB member, said the city faces a crucial decision.

"It really does come down to Minneapolis at some point," McDonough said, adding that some kind of tunnel option "seems to satisfy the most issues for the reasonable amount of money."

"Minneapolis really has to decide does that make sense for everybody or … to just say, 'We're not going to allow Southwest to be built because we don't know that makes sense for us,' " he said.

Mayor Betsy Hodges on Friday said the Met Council hasn't provided enough details to Minneapolis residents on how the latest tunnel plan would work. But she said its construction would be "even worse" than the previous tunnel plan, with "more loud pile driving, more truck traffic, to remove more dirt.

"We already know what would work: rerouting freight out of the Kenilworth corridor," she said.

Overriding objections?

State law requires the Met Council to seek the consent of the five cities along the nearly 16-mile route.

The statute provides for weeks of give-and-take, during which the cities can offer amendments that the agency can adopt or reject.

At the CTIB meeting last week, Anoka County Commissioner Matt Look asked what happens if there's no agreement. "Is there an override function of the Met Council?"

Met Council transit developer Mark Fuhrmann said if a city repeatedly rejected a plan after adjustments were made, "the council by statute does have authority then to consider what it wants to do. Does it want to continue that cycle … or if it wants to move ahead."

He said overriding a city would be "an option for advancing the project."

The agency has never pushed a light-rail project forward over the dissent of a city.

Met Council Chairwoman Susan Haigh has said she wants the consent of the cities but hasn't said whether the agency would move ahead without it.

Pat Doyle • 612-673-4504